He's talking about logging onto your Solarwinds server. Then clicking on Start, All Programs, Solarwinds Orion, Syslog and SNMP Traps, then select Syslog Viewer. Once the application opens up you'll see the Syslog Viewer. Then click on the icon I've circled in this image.
Also check how long you retain syslog messages for. Do this by opening Solarwinds in your browser. Click on Settings (top right hand corner). The click on Orion Polling (right hand side of page in the Settings section). Scroll down to Database Settings and look for Syslog Messages Retention. I have mine set for 21 days but you could drop this down to 7 days.
And lastly just double check what you've configured on your nodes to send out in the way of syslogs. They should say 'logging trap critical'.